As one who has walked the same path...there is no straight forward formula regarding adjunct pay+/-child care=worth. It is painfully
not that easy. I am afraid I've missed reference to whether your husband is in academia, and from there, if he understands the industry and can empathize. Mine couldn't, and this became a much more profound obstacle than "the bottom line."
I, too, found myself adjuncting in comp and outside my area. The saints sent their blessings with getting my oldest into the college children's center but, alas, never would the faculty benefit be applied to an adjunct. Yes, we paid dearly, and doubly so when #2 came along (but got sibling priority!). And, yes, in mere accounting terms, sometimes, what got paid vs what I got paid barely broke even.
We still lived like grad students but we were not starving: my husband's law career was definitely picking up speed. As Watermarkup inquired
Can't your husband pull himself out of his office for three hours a week so he can watch junior while you teach one class?
mine couldn't. He was never called out of a meeting because of a sick child; he didn't adjust his weekend billable hours, etc. The issue seemed to come down to what I did--who I was by academic training--wasn't categorically comparable to the other law firm spouses. They all seemed to be attorneys or stay-at-home-moms with all the socio-status bells and whistles. Correspondingly, I got the ultimatum--get a real job or stay at home. He would also make it a point to announce he was not speaking to me because I didn't make enough money to make it worth speaking to me.
Whatever the accounting, I looked at my teaching and having my children at the children's center as an investment in all of our futures. The contact alone with the children's center was a godsend. Teaching comp as a grad student significantly altered my perception of myself on the job market/employed, but I was still on the job market/employed. That somehow motherhood would (should) change that perception so much more drastically than fatherhood should (would) (not) change a male's perspective...
Wanderluster, I don't wish this infantile situation on you or anyone. Do let us know what you've decided.